This invention relates to the safety and simplicity of devices designed for the dispensing and cutting of transparent, adhesive, masking and strapping tape or any other long, thin flat material stored and dispensed from a roll.
A number of patents have been granted for devices that dispense and cut long, thin material wound on a roll. While some have addressed the problem of accidental injury, none of the previous art adequately simplifies the mechanism to reduce the effort, size or cost of a tape dispenser that provides a level of protection from accidental contact with the cutting blade when device is not in use or when dispensing, cutting, or loading tape.
Several approaches for protecting users of tape dispensers from potential harm from the cutting edge of a tape dispenser appear in these patents. Among those approaches is that described in U.S. Pat. No. 6,296,033 issued Oct. 2, 2001 to Alan Clements which has a removable guard 38 formed from a pliable material which is removably attached to and extends beyond cutting blade 32. The extended length of the guard 38 beyond the outer edge of cutting blade 32 limits impact of the blade on objects and the user. (See FIG. 3 and column 3, lines 28–40). The Clements patent also discloses use of a less pliable guard which is scored along a bendline to form a resilient hinge (See column 3, lines 40–44). Movement of the guard 38 out of its guarded position over the serrated blade 32 is achieved by the tape as it is drawn off the tape roll and toward contact with the blade. The tape pulls the shield 38 away from the blade to facilitate the latter's penetration and cutting of the tape. (See FIG. 4 and column 3, lines 60, et seq.).
Another approach to guarding the cutting edge of a tape dispenser from unwanted harm to the user is use of a pivoting shield of the type disclosed in U.S. Pat. Nos. 5,456,790 and 5,393,367 issued to Chen, et al. These patents disclose a rigid pivoted shield 20 that is normally biased into a protective position over the cutting blade 30. The shield 20 is pivoted out of its protective position as the tape dispenser is tilted to dispense tape, thereby allowing cutting engagement of the blade 33 with the tape (See FIGS. 5–6 and column 4, lines 42–47 of the '790 patent).
Other patents approach the problem of sharp cutting blades with mechanisms that retract the blade until it is needed to cut the tape. In U.S. Pat. No. 5,641,377 issued Jun. 24, 1997 to Chung, et al., a hand held dispenser employs a mechanism which extends the blade 41 when pressure is applied on a pivoting “wiper” 49 extending from the body of the dispenser (See FIGS. 2–3 and column 4, lines 49, et seq.). A very similar arrangement for a retractable blade is disclosed in U.S. Pat. No. 5,849,144 issued on Dec. 15, 1998 to Tang, et al.
Several different embodiments of blade protection useable in dispensers of sheet material are disclosed in U.S. Pat. No. 6,039,102 issued Mar. 21, 2002 to Sadrakula, et al.
U.S. Pat. No. 4,818,329 issued Apr. 4, 1989 to Tutas, et al. discloses a rigid, spring-biased movable guard 43 over cutting blade 148 mounted on a rotatable shaft 152 which is normally spring biased to cover the blade but can be rotated out of its covering position when the dispenser is rotated into position to dispense tape (See FIGS. 2–3 and column 7, lines 20–49).